Air cleaner



Feb. 9, 1937. w w LQWTHER 2,069,889

AIR CLEANER Filed Dec. 17, 1934 i 7 l 1; I g i i I l 'l l I I i l l I 7i 7 INVENTOE Wilfred W. Lowfher BY H15 ATTORNEY;

Patented Feb. 9, 1937 U N l T E T T E S PATENT QFEE AIR CLEANERApplication December 1'7, 1934, Serial No. 757,829

9 Claims.

My present invention relates to air cleaners and is in the nature of animprovement on or modification of the air cleaner claimed in my pendingapplications, S. N. 702,482 and 702,483, filed of date December 15,1933, which applications have matured into Patents 2,000,706, issued May'7, 1935, and 1,991,758, issued February 19, 1935, respectively. Thisinvention relates particularly to an improvement in the oil Well, oilcup and the disposition thereof in respect to the casing, air intake andscreens of the air cleaner.

Generally stated, the invention consists of the novel devices,combination of devices and arrangement of parts hereinafter describedand defined in the claims.

In the accompanying drawing, which illustrates the invention, likecharacters indicate like parts throughout the several views.

Referring to the drawing:

Fig. l is a View partly in side elevation and partly in vertical sectionshowing an air cleaner involving my invention; and

Fig. 2 is a horizontal section taken on the line 2-2 of Fig. 1.

As shown, the air cleaner involves an outer casing or shell that ispreferably in the form of an upright cylinder 3, the lower end of whichis primarily open. An axial air intake tube 4 extends downward throughthe casing 3. A large or main oil well 5 of cup-shaped form istelescoped onto the lower end of the casing 3 and closes the lower endof the latter.

As a means for securely but detachably holding the oil well telescopedonto the casing, nutequipped bolts 8 are passed through lugs l on thecasing and through the ends of a bar 8 that is applied to the bottom ofthe oil Well. At the upper end of the casing is an air outlet chamher 9that is formed between baiile plates 10 and H. The upper bafiie I issecured to the upper end of the inlet tube 4 and to the upper end of thecasing. The lower bafile H is secured to the air tube 4 and to thecasing 3 at a point considerably below a lateral air outlet passage I2,which latter is adapted and intended to be connected to the carburetorof an internal combustion engine. The lower baiile plate I I constitutesthe bottom of the outlet chamber 9 and is provided with an annular airpassage is.

Located within and secured with respect to the bottom of the oil well isan upwardly opening oil containing cup shaped receptacle N that is ofmuch less diameter than the oil well, of considerably greater diameterthan the lower end of the intake tube 4 which extends therein in opposedrelation to the bottom of said receptacle I4, and the upper edge ofwhich is considerably above the plane of the lower edge of the airintake tube and approximately even with the normal oil level in saidWell, providing between the 5 spaced walls of the inlet tube 4 andcup-shaped receptacle I4 a primary outlet passageway for air to theinterior of said casing 3, and primary inlet for oil to said receptaclefrom said Well 5, during certain operating conditions due todifferencesin pressures in said inlet tube 4 and outlet 12. This cup shapedreceptacle M has as an important feature thereof circumferentiallyspaced ports or passages [5 in its vertical wall that are locatedapproximately in the plane of the lower end of said air intake tube 4.The oil well will normally be filled with oil approximately to the levelof the upper edge of said cup M. The important action that takes placewith the structure just noted will be more fully considered in thedescription of the operation.

Within the casing surrounding the air intake tube is an annular screenpreferably made up of woven wire screen elements. These screen elementsl6 may take various forms, but as shown, are of the type and arrangementdisclosed and claimed in the application of Frank A. Donaldson, entitledAir cleaner, filed of even date herewith.

An expanded air intake chamber I l is, in the structure illustrated,formed at the upper end of the air intake 4 by an annular bafile l8secured to the upper edge of the casing and provided withcircumierentially spaced air ports I9 preferably of the arrangementdisclosed and claimed in the pending application of Frank A. Donaldson,S. N. 722,458, filed of date April 26, 1934, which application hasmatured into Patent No. 1,992,025, issued February 19, 1935.

Operation When the engine is in operation, partial vacuum will beproduced in the air chamber 9 which drop in pressure in said casingabove the body of oil in the well 5 causes air to rush downwardlythrough the air intake tube 9 and against or through the oil in the cupIt. By the inrush of air, the oil will be displaced and carried upwardthrough the annular space between the lower end of the air tube and therim of the cup, and from thence will be carried upward into the screenelements. The extent to which the air will carry the oil upward throughthe screen elements will, of course, depend largely upon the speed ofthe engine and the velocity of the air. Before the oil reaches theuppermost screen element, however, it will be released from the aircurrent and will flow back over and through the screens. In running downonto and through the screens, the oil will form films over the openingsof the screens and through which the air must pass, so that all the dustcarried by the air will be taken from the air and returned with the oildownward and back to the oil well.

At low engine speeds, when the air flow through the cleaner isintermittent or pulsatory, the oil cup M will be maintained onlypartially filled with oil as a large part thereof will be constantlydisplaced and carried into the screen chamber and oil well, thereby,building up the head of oil in the well above the upper edge of the oilcup. Under this pulsating action, at low engine speeds, oil will to adesired extent overflow the upper edge of the cup and will also beintermittently injected into the air stream within the partially filledcup through holes i5, due to back surges filled cup between suctionimpulses upon the body of oil in the well. The upper edge of the cup andopenings l5 in the side wall thereof thus serving to maintain aregulated body of oil in the cup l4 and to supply oil to the air streamin regulated amounts,- thereby materially increasing the efliciency ofthe cleaner at low engine speeds.

Under certain conditions it has been found that oil will cease to flowthrough the holes I 5 into the cup when the engine is operated someplace between three-fourths full load and full load, for example, and.that for a period there will be substantially no movement of either airor oil through the holes l5,but that under further increased load, thepressure in the cup becomes so great that air passes outwardly throughthe holes l5 and bubbles up through the annular head of oil. This actionhas been found to be highly important for the reason that a point isreached near maximum engine speed or load where the air flow past theupper edge of the cup is at such great velocity and is so steady and theair pressure above the cup is so relatively great that the oil remainsbanked up in the head above and outward of the cup and practicallyceases to overflow the upper edge of the cup. Now it will be obviousthat in the absence of the holes l5 this failure of oil to enter the airstream by overflowing the cup under conditions encountered near maximumload would result in rapid starving of the intercepting screens 1/ andgreat loss in air cleaning efiiciency if operation near maximum engineload were continued for an extended period. However, when the holes I 5are provided the outward movement of air through the holes l5 does, inbubbling through the annular head of oil, raise some of the oil in thepath of rapidly expanding air above and outward of the cup and this oilis delivered to the screens y in sufficient quantities to retain theefliciency of the cleaner during prolonged periods of engine operationnear maximum load. There is little danger in getting an over supply ofoil from this source due to the relatively small volume and low velocityof the air passed through the holes l5 and the relatively low velocityof the main air stream at the points Where it intercepts the oil raisedby air from the holes I5.

At high engine speeds, however, the movement of the air through thecleaner will be nearly continuous or non-pulsatory and the increasedvelocity and constancy of pressure will displace completely orsubstantially all of the oil in the cup I4, and thereafter the airstream will be supplied with oil which will continually overflow theupper edge of the cup I 4 and due to a balancing of pressure in the cupand well the holes l5 in the cup M will then be substantiallyinefiective.

The point is that at low engine speeds, where most cleaners of the fluidtype become relatively 5 ineflicient, oil is supplied to the air streamnot only from over the upper edge of the cup [4 but through the openingsl5 therein, thereby increasing materially the amount of oil supplied tothe air stream at low speeds, with a resultant rate of 10 increase inefficiency at low speeds; but at high speeds when cleaners of thisgeneral character are apt to supply so much oil to the air stream thatsome of the oil will be carried completely through the cleaner and intothe engine, the holes l5 l5 become substantially ineffective, therebymaterially reducing the amount of oil fed to the air stream and the cupl4 serves to limit the amount of oil picked up by the air stream to anextent necessary to insure against the carrying over of 20 the oilthrough the cleaner. The apertured cup- I4 serves as a metering deviceto increase the amount of oil supplied to the air at low engine speedsand reduce the same at high engine speeds.

From the foregoing it is evident that the oil cup 25 which is locatedwithin the oil well should not only be spaced from the delivery end ofthe air intake tube, but should be extended considerably above the planeof the lower edge of the latter and that the cup be provided in the sidewalls 30 with perforations or oil passages located well above its bottomand below its upper edge. It has been found that the best results havebeen obtained by placing the said perforations substantially as shown orapproximately in the plane of 35 the lower end of the air intake tube.Obviously, certain modifications as to details of construction andarrangement of parts may be made within the scope of the inventionherein disclosed and claimed.

The screens described afford the best known form of air impervious oiland dust-intercepting means.

What I claim is:

1. An air cleaner comprising a casing pro- 45 vided with an oil well andhaving an air inlet and an air outlet, dust and oil-intercepting meanslocated in said casing between said oil well and said air outlet, and acup-shaped receptacle supported in said oil well in spaced opposedrelation to the 50 discharge end of this air inlet and having its upperend surrounding the inner end portion of said inlet, whereby dust'ladenair in passing to said intercepting means over the upper edge of saidreceptacle will impinge upon and displace 55 the body of oil in saidreceptacle, and metering opgiir g s inwthesidelwall o f said receptacleto control the-flQlV...QimilQtliiiethrough from the oi-Pwellto the airstream under operating condltiOHS. i Q Q 0 2 In.,an air cleaner, thecombination with a casing having an outlet, an oil well in the base ofsaid casing and an air intake tube leading into said well, a screenextending between said inlet and outlet above said oil well, and apartition wall supported within said oil wllandarranged-Jim,

to provide an oil containing cup-shaped receptacle in opposed relationto the delivery end of said air intake tube and having its upper edgedisposed above the normal oil level in said oil well, and oil and aircontrolling openings in the side wall of said receptacle below thenormal oil level in said oil well.

3. In an air cleaner, the combination with a casing having an oil welland an axially disposed air intake tube extending into said well, ofascreen within said casing and surrounding said air intake tube above theoil level in said well, and said well including a cup-shaped receptaclethe side walls of which are spaced from the walls of said well and fromthe discharge end portion of said air intake tube, whereby to provide aprimary air passage between the discharge end portion of said inlet tubeand the upper side wall portions of said receptacle communicating withsaid casing above the normal oil level within said well and a portextending through the side wall of said receptacle and establishingcommunication between the interior of said receptacle and said wellbelow the normal oil level adapted under varying changes in pressurewithin said receptacle and casing to control the flow of oil to saidreceptacle and air to said well.

4. The structure defined in claim 3 in which the side walls of saidreceptacle are provided with a series of circumferentially spaced oiland air controlling ports arranged adjacent the discharge end of the airintake tube.

5. An air cleaner comprising a casing having an oil well, an air inletand air outlet, said inlet and outlet being arranged respectively belowand above the normal oil level in said well, dust and oil interceptingmeans located between said inlet and outlet in normal spaced relation tothe body of oil in said well, partition walls arranged in the oil wellof said casing to provide a cupshaped chamber into which the dischargeend of said air inlet extends, a primary air passageway formed by saidpartition wall approximately at the normal level of the body of oil insaid well, and other passageways in said chamber In communication withsaid well below the oil level adapted under certain operating conditionsin said inlet and outlet to supply oil to said chamher, and under otheroperating conditions to conduct inlet air from said chamber to saidwell.

6. In an air cleaner, the combination with a casing having an oil wellat its bottom and an air intake tube leading into said well, of dust andoil intercepting means within said casing surrounding said air intaketube above said oil well, and an oil containing cup-shaped receptaclesupported within said oil well spaced from the walls of said well and inopposed relation to the delivery end of said air intake tube, the sidewalls of said receptacle extending above the delivery end of the intaketube and being provided with air and oil controlling ports below itsupper edge and above the bottom thereof.

'7. In an air cleaner, the combination with a casing having an oil wellin its bottom and an air intake tube leading into said well, dust andoil intercepting means within said casing above said oil well, and saidoil well including partition walls defining a cup-shaped receptaclepositioned in opposed spaced relation to the delivery end of said intaketube, the said walls of said receptacle being laterally spaced from theside walls of the well and delivery end of said intake tube andproviding a primary air outlet from the delivery end of said tube to apoint above the normal oil level in the well, said receptacle wallshaving metering ports intermediate its upper and lower ends to controlthe flow of oil to said receptacle and the discharge of air from saidreceptacle to said well under varying operating conditions within saidcasing.

8. An air cleaner comprising a casing provided with an oil well, an airoutlet leading from the casing at a point upwardly spaced from said oilwell, an upwardly opening receptacle provided by a partition walllocated in said oil well, a downwardly directed air inlet passagewayarranged to discharge into said receptacle, metering openings in thepartition wall of said upwardly opening receptacle intermediate theupper and lower edges thereof, and an upwardly directed primary airpassageway between the walls of said inlet passageway and receptacle incommunication with the interior of the casing above the oil in the well,whereby said metering openings are rendered effective to control thesupply of oil from the well to the air stream in said primary airpassageway through displacement of oil in said receptacle below saidmetering openings by impingement of the air stream thereon.

9. In an air cleaner, a casing having an oil well, an air outlet fromthe casing, an air inlet passage opening into the oil well, an upwardlyopening receptacle supported in said oil well in opposed relation to thedischarge end of the air inlet passage and having its side walls spacedfrom the walls of the well and from the discharge portion of said airintake passage, whereby the dustladen air stream in passing from the airinlet passage and over the upper edge of said receptacle will impingeupon and displace the body of oil in said receptacle, and meteringopenings in the side wall of said receptacle to control the supply ofoil from the oil well to said air stream, under operating conditions.

WILFRED W. LOWTHER.

